COVID-19 crisis and resilience of tourism SME’s: a focus on policy responses

the resilience of small and medium-sized tourism enterprises during crisis periods. Proper selection and implementation of these policies is one of the major challenges facing tourism policy makers. The aim of this article is to propose a systematic framework for selecting government supportive policies that contribute effectively to resilience improvements of tourism SMEs during the COVID-19 disaster. After reading the international reports of the COVID-19 disaster carefully and using similar research findings in past disasters as the preliminary stage of framework development, a comprehensive list of country-based recovery policy responses as well as the critical success factors (CSFs) of tourism SMEs in the crisis recovery phase was extracted and then finalized in an expert-oriented process. In the next stage, the Z-SWARA was applied to weigh the CSFs. Then, four Z-MADM methods were implemented to rank the alternatives, and finally, the results were compounded with BORDA technique. The results of implementing the proposed framework in Iran’s tourism industry show that Disaster management planning capability, as well as Marketing management are the most important CSFs. Also, financial support including direct lending and grants and subsidies to SMEs have been identified as the most effective governments’ supportive policies to recover tourism SMEs in the post-disaster phase. Generally, these results have valuable implications for different stakeholders such as policymakers, practitioners and researchers in the tourism industr

Uncertain Multi-Criteria Optimization Problems

Most real-world search and optimization problems naturally involve multiple criteria as objectives. Generally, symmetry, asymmetry, and anti-symmetry are basic characteristics of binary relationships used when modeling optimization problems. Moreover, the notion of symmetry has appeared in many articles about uncertainty theories that are employed in multi-criteria problems. Different solutions may produce trade-offs (conflicting scenarios) among different objectives. A better solution with respect to one objective may compromise other objectives. There are various factors that need to be considered to address the problems in multidisciplinary research, which is critical for the overall sustainability of human development and activity. In this regard, in recent decades, decision-making theory has been the subject of intense research activities due to its wide applications in different areas. The decision-making theory approach has become an important means to provide real-time solutions to uncertainty problems. Theories such as probability theory, fuzzy set theory, type-2 fuzzy set theory, rough set, and uncertainty theory, available in the existing literature, deal with such uncertainties. Nevertheless, the uncertain multi-criteria characteristics in such problems have not yet been explored in depth, and there is much left to be achieved in this direction. Hence, different mathematical models of real-life multi-criteria optimization problems can be developed in various uncertain frameworks with special emphasis on optimization problems

Transformation Rules for Z

Z is a formal specification language combining typed set theory, predicate calculus, and a schema calculus. This paper describes an extension of Z that allows transformation and reasoning rules to be written in a Z-like notation. This gives a high-level, declarative, way of specifying transformations of Z terms, which makes it easier to build new Z manipulation tools. We describe the syntax and semantics of these rules, plus some example reasoning engines that use sets of rules to manipulate Z terms. The utility of these rules is demonstrated by discussing two sets of rules. One set defines expansion of Z schema expressions. The other set is used by the ZLive animator to preprocess Z expressions into a form more suitable for animation.

Specification comprehension reducing the complexity of specifications

The objective of this work is to support the process of specification comprehension. The majority of comprehension problems goes back to the complexity of size, and the basic idea is to reduce the complexity of specifications by focusing on those parts which are necessary to solve a specific problem at hand. It is suggested to generate well-defined partial specifications such as specification slices and chunks. A prototype for Z-specifications has been implemented and used to asses the approach. The evaluation shows that, especially with larger specifications, the generation of partial specifications is efficient and effective. This work suggests to visualize dependencies that are hidden in the specification. Similar to program comprehension approaches the calculation of specification slices and chunks also depends on the identification of control-, data- and syntactic dependencies. As programming-language-like notions of dependencies are not applicable for specification languages this work introduces the notions of control-, data- and syntactic dependencies in specifications. Here, the basic idea is to look at dependencies between pre- and post-condition parts of the specification at hand. For the identification of dependencies it is suggested to transform the specification to a graph structure. The transformation depends on the specification language at hand and this work provides transformation rules for Z. However, the approach is applicable to several specification languages as the graph and the rules for the identification of dependencies are defined in a language-independent manner.Ziel der Arbeit ist, den VerstÃ$ndnisprozess (fÃr Wartungsfragen) bei Spezifikationen durch Verringerung der KomplexitÃ$t mittels Fokussieren auf relevante Teile zu unterstÃtzen. Im Fachgebiet des Programm-Verstehens gibt es bekannte Konzepte um den Umfang zu reduzieren und sicherzustellen, dass wichtige Informationen nicht verloren gehen: es sind dies die Konzepte der Erzeugung von Slices und Chunks. Diese Arbeit greift diese Konzepte der PartialitÃ$t auf und definiert Slices und Chunks fÃr Spezifikationen. Ein einfacher Prototyp fÃr Z-Spezifikationen wurde entwickelt. Die mit diesem Prototyp durchgefÃhrte Evaluation des Ansatzes zeigt, dass das Konzept der partiellen Spezifikation sehr effektiv ist. Vor allem bei grÃÃeren Spezifikationen kommt es zu einer starken Reduktion des Umfangs der partiellen Spezifikationen. Die Erzeugung von partiellen Spezifikationen und das Sichtbarmachen versteckter AbhÃ$ngigkeiten setzen die Identifizierung von Kontroll-, Daten- und SyntaxabhÃ$ngigkeiten voraus. Aufgrund der deklarativen Natur vieler Spezifikationssprachen sind es vor allem KontrollabhÃ$ngigkeiten die nicht so einfach wie bei imperativen Programmiersprachen zu identifizieren sind. Diese Arbeit definiert AbhÃ$ngigkeiten in Spezifikationen, wobei es bei KontrollabhÃ$ngigkeiten auf die Identifizierung von AbhÃ$ngigkeiten zwischen Vor- und Nachbedingungen zurÃckgreift. Zur effizienten Identifizierung der AbhÃ$ngigkeiten wird eine Transformation in einen Graphen vorgeschlagen. Die Erzeugung des Graphen hÃ$ngt von der gewÃ$hlten Spezifikationssprache ab. Der Graph und die Regeln zur Identifizierung von AbhÃ$ngigkeiten sind jedoch so allgemein gehalten, sodass der Ansatz auf unterschiedliche Spezifikationssprachen anwendbar ist. Zur Veranschaulichung werden Regeln zum Transformieren von Z-Spezifikationen angegeben.Andreas BollinZsfassung in dt. SpracheKlagenfurt, Univ., Diss., 2004KB2004 26OeBB(VLID)241626